Power converter



Aug. 14, 1951 G. H. RAMSEY PowER CONVERTER 5 Sheets-Sheet l Filed May 8,1948 wml GEORGE M Q4/1455) Aug 14, 1951 G. H. RAMSEY 2,564,212

PowER CONVERTER l Filed May 8' 1948 5 sheets-sheet 2 Aug. 14, 1951 G. H.RAMSEY 2,564,212

POWER CONVERTER Filed May 8, 1948 5 Sheets-Sheet 5 wv www @sens M,2A/user Patented Aug. 14, 1951 UNITED STATES PATENT OFFICE OWE-RCGNVERTER George H. Ramsey, Rollin-Mo.

Application May 8, 1948, Serial No. 25,970

7 Claims.

This invention relates to a power converter; more specically, tohydraulic apparatus having the combined function of a clutch andtransmission and which is useful in automobiles and similar mechanisms.

The use of hydraulic clutches for automobiles and the like and theadvantages obtained thereby, such as smooth acceleration, are wellknown. Many attempts have been made to simplify the lconstruction of thedriving mechanism of an automobile, but in most instances a separateclutch and transmission are required. Transmiss'ons of the well-knowntype are usually jerky in operation and much is to ybe desired in theway of improvement to provide smooth acceleration, particularly whenstarting from a standstill. While automatic transmissions have beendevised, these are generally cumbersome and expensive in constructionand involve large numbers of parts requiring frequent servicing.

An object of the present invention is to provide a combined hydraulicclutch and transmisslon device in a single unit of relatively simpleconstruction and which is devoid of the above-named disadvantages ofwell-known structures.

A more specific object of my invention is to provide a hydraulictransmission and Vclutch mechanism which converts rotating mechanicalpower of any speed and torque into a power of lower rotative speed andhigher torque.

A still more specific object of my invention is to provide a hydraulicclutch and transmission unit including sliding piston-like blocks whichunit operates on the principle of pressure balance between centrifugalforce of the sliding blocks against oil pressure developed in the unitby a rotating eccentric which transmits torque to the driven shaft inthe form of a series of liquid pressure impulses.

The invention in its broadest aspects comprises a rotating eccentricallymounted drum connected to a driving shaft, which drum is containedwithin a larger outside drum that is connected to the driven shaft, thespace ybetween the drums being lled with oil or other suitable hydrauliciiuid. A pair of substantially radially extending slidable plates areprovided between the drums and arranged so that they will always closethe gap between the rotating eccentric and the outside drum irrespectiveof the position to which the eccentric is rotated, so as to continuouslyform two separate chambers whose volumes are alternately increased anddecreased in succession causing pressure surges in the oil which aretransmitted Vto the slidable plates and, in turn, to the outside drumand driven member. To obtain greater torque, as in the case of startinga vehicle, itis necessary merely to allow the driving member androtating eccentric to operate at higher speed which, in turn, causesfaster pressure impulses and develops greater centrifugal force on theradially outwardly slidable blocks.

Other objects and advantages will'become apparent from the study of thespecication taken in conjunction with the accompanying drawings inwhich:

Figure l is a cross-sectional view of a combined hydraulic clutch andtransmission mechanism embodying the principles of the present inventionand taken at right angles to the axes of the driving and driven members,that is, along line I-I of Figure 2;

Figure 2 is a longitudinal cross-sectional View taken along the line 2-2of Figure 1;

Figure 3 is an enlarged iragmentary longitudinal cross-sectional viewshowing more clearly the central portion of the structure of Figure 2,illustrating the position of parts when the rotating eccentric is atrest;

Figure 4 is a longitudinal cross-sectional view taken along line 4--4 ofFigure 1 to show more clearly the sliding pressure blocks; and,

Figure 5 Vis a perspective view, shown partly broken away, of themechanism show'n in Figures 1 to 4, inclusive.

Referring more particularly to the figures, numeral I denotes a drivingor driver shaft which may be connected to any suitable source of motivepower or prime mover, such as a gasoline engine or electric motor. ShaftI is directly connected by means of splines or keys 2 to aneccentrically mounted inner drum or rotating ec-` centric 3. Therotating eccentric 3 is in a form of a circular drum whose axis isoffset with respect to that of the drive shaft I. A portion of reduceddiameter 2a of the drive shaft is preferably tted in a hole boredaxially of the driven shaft 4 and may be surrounded by bearing 4a.

Such arrangement adds to the rigidity. of the unit but is not necessary.Rigidly secured to the driven shaft Il by means of splines or keys suchas 5 is an outer drum 6 which is iilled with oil or other suitablehydraulic liquid. The outer drum 6 may be of any suitable construction,for example, it may comprise end plates 6a and 6b bolted together and toa cylindrical plate I by means of bolts 8. There is no mechanicalconnection between the inside and outside drums.

In order to provide an oil-tight seal between the inner and outer drums3 and 6, respectively,

suitable gaskets S and Iii are provided on end flanges integrally formedon inner drum 3. Such gaskets may be of the split type and may be seatedin concentric grooves so that upon developrnent of high oil pressure thelips of the gasket would become mo'e tightly pressed against theadjoining surfaces.

Sleeves or bearings 3c and 3b are provided between the inner and outerdrums to permit free relative rotation, also the radially outward forcel veloped in the outside drum is neutralized by applying it to the innerdrum or eccentric. This stabilizes the positions of the outer and innerdrums during operation of the mechanism.

integrally secured to the cylindrical plate l of the outer drum are apair of radially extending stationary plates ll and l2, having groovestherein into which are slidable, radially movable plates I3 and lil,respectively, which plates are normally biased into engagement with thesurface of the rotating eccentric 5i at all `times oyrneans of springsiii and l5, respectively, contained in the grooves. It will be seentherefore that the stationary and movable plates effectively divide thespace -between the outer and inner drums into two .compartments whosevolunies will vary as the result of rotation of eccentric 3. That is, asthe lobe of the eccentric enters one of the semi-circular chambers orcompartments, it reduces 'the volume thereof and sdueezes or tends tocompress the liquid oil contained therein developing a pressure pulsewhic is transmitted to the outer drum as will 'ce described`hereinafter.

if no other structure were provided than `that described the oilpressure might assume abnormal and explosive proportions, or would causethe whole unit to rotate as one piece as in a hydraulic clutch. Toprevent this possibility and to control the oil pressure at all times,substantial y radially slidable blocks il and i8 are provided along aportion of the surface of `eccentric 3, which clocks have arcuateworking surfaces conforming to the periphery of the rotating eccentricand act in effect as pistons for developing liquid pressure in therespective semicircular chambers. `'Blocks il and i3 have integrallysecured to the rear central portions thereof arr'ns iQ and 2Qrespectively having at the free ends thereof integrally formed T-shapedends 2! and 22 respectively which Yare slidahle in correspondinglyT-shaped slots, such as 2id formed in the periphery of a slidable cam23. The slidable cain 23 is generally .of the shape of a truncate-d conewhich encircles and is slidable along the drive shaft portion 2a. Ahelical spring encircling the drive shaft portion 2n. normally biasescam 23 toward the left, as viewed in Figure 2, so as to cause arms i9and 2li and their respective fr-shaped ends to move substantiallyradially inwardly to the full line position shown in Figure 3, pullingsliding` clocks 5'! and 'i8 radially inwardly; therefore, allow escapeof oil from one semi-circular chamber to the other underneath slidaoleplates I3 and le; that is, for example, from the high pressure chamber'shown at the top of Figure 1 to the low pressure-chamber shown at theAbottom thereof. It will he noted that plates i3 and I4 always ridealong the end peripheral portion of the outer surface of eccentric 3thereby allowing an oil escape opening to form between the siidableplates 3 and la and blocks I'! and it. rEhe operation of the devicehereinaliore descrilced'is as fellows:

vdivide Athe Assume that the device is installed on a vehicle and thatdriven shaft a and the vehicle are at rest. As the driving shaft l isrotated by the engine it will rotate eccentric 3 mechanically coupledthereto. Since the movable plates iii and Hi are spring pressed againstthe peripheral surface of the rotating eccentric 3, there at all timesbe provided two separate semicircular chambers. the lohe Yportion ofeccehtrc 3 enters these chambers in succession (it being shown extendinginto the upper chan ber in Figure l) it will cause a reduction of volumein the respective chambers, therefore squeezing or tending to compressthe oil in the chamber thereby developing substantial pressure. As thepressure tend-s to become excessive, it will force pressure blocks Eland i3 radially inwardly so as to allor1 escape of the oil from the highpressure to the low pressure chamber, that is, from the upper chamber tofthe lower chamber when ythe parte :are as illustrated yin :Figuze i..Ythe `oil flowing under the movable plates it M. Since the two blocks iland l .are .mechanically coupled hy means of their T-slct connections tocam they provide'the same sized oil escape openings, in view of the factthat they are at the .same distance :or positions relative to theoutside surface Yof the eccentric. The oil will thus flow .back vandfcrth'bejtween compartments throughthese openings. The J-shaped .portionof .the ,rotating eccentric A may 4he provided with grooves Sd to permittransfer of .liquid ice-tween chambers even when the slidaole platerides on portion 3c.

,As the rotating eccentric 3 `is rotated bythe driving shaft.centrifugal force tends to cause sliding clocks il' and i3 to movesubstantially radially outwardly iso as to compress the liquid containedin the respective chambers. The oil pressure is built up Yone oilcompartment at a time, Athat is, as the eccentric rotates it squeeaes orreduces the volume of. one chamber while `inrnea-sing that of the other.During each half revolution `the volume of one oil compartment willchange from a maximum to a minimum. Durng the next half revolution suchoil compartment will change from a minimum to a maximum volume again.Thus, an unbalanced force would be created which will cause the outsidedrum :6 to rotate oy virtue of the fact that there is a difference intotal areas of the two sets of plates (stationary and movable) which oilcompartments. The net pressure on Vthese sets of 'plates will be in agiven direction and will cause a series of impulses on Lthe plates whichin turn ywill effect Irotation oi' lthe outer drum and driven shaft 4.

`tion of equilibrium.

When the driving shaft 'is stopped, the blocks are automatically 'movedradially inwardly, from the dotted vto the full line position shown inFigure 3, by -rneans of biasing spring 2'4 so that channels or openingswill he provided for oil `to flow underneath Vplates i3 and I4 'from onecompartment to the other. When the unit is in this condition, no powercan he developed 'cecause every time the oil pressure builds up it willbe relieved. Such can be thefease if centrifugal force does not act onthe vsliding blocks to push them outwardly.

The essential theory or key to the operation of the power converterinvolving the present inyven1 ',ion,'lies in the balancing ofcentrifugal vforce of the sliding blocks against the oil pressuredeveloped by the rotating eccentric which transmits torque to the drivenshaft. The oil pressure is balanced against the speed of the drivingshaft and oil is allowed to ilow if the pressure can overcome thecentrifgal force of the depressible blocks. When the centrifual force isgreat, the oil pressure may be great. When the rotating eccentric turnsrapidly a high oil pressure is developed in cycles which occur twiceeach revolution, since there are two oil compartments acting ultimatelyas high pressure compartments. The successive power impulses continuallyproduced during such rotation impart a torque to the driven shaft.

When the driven shaft has been brought up to the speed of the drivingshaft which is done smoothly since all power is transmitted solelythrough oil, the centrifugal force on the sliding blocks is great,wheres the oil pressure required to maintain rotation is moderate. Theunit is then in an operating position wherein there are practically nomoving parts.

in arcuate oil space is provided under each sliding block so that whenthe blocks are moved radially inwardly they will occupy such space, butwhen they move radially outwardly the oil will flow through andunderneath them through holes Ila and I8a extending through the blocks.In this manner, the total amount of oil required inside the powerconverter is constant. These holes in the sliding blocks also help evenout the position .of the sliding blocks and even out the inward forceexerted by the oil pressure.

The power converter described canv serve a f variety of applicationssimply by changing the weight of the sliding blocks. Such simplemodication changes the output of the power converterbecause of theincreased effect of centrifugal force.

The power converter is compensating in its action because as more poweris required of it the driving shaft of the engine or prime moversupplying the power will be allowed to turn faster. When the speeds ofboth shafts are the same, that is, when the output or driven shaft hasbeen brought up to the speed of the driving shaft, then the powerconverter rotates as a unit with no relatively moving parts thereinwhich would cause wear.

'I'he power converter embodied in the present invention is particularlyadaptable for use in electric motor drives and internal combustionengine drives. Such unit has a great variety of possible uses. replacethe conventional transmission and clutch and would have the outstandingadvantage of allowing the engine to rotate rapidly enough to developmaximum horsepower even during starting. Although a reverse gear wouldstill be needed, there would nevertheless be a tremendous saving in thetotal number of parts required. The power converter of the presentinvention is also useful in tractors, well drilling apparatus and a hostof other uses wherever rotating machinery is required. With slightmodification, it may be used to advantage in mining, that is, on miningelevators, particularly since it is adaptable to hold a constant rate ofdescent of the elevator and also act as a transmission when the elevatoris being raised.

Thus it will be seen that I have provided a relatively simple andinexpensive hydraulic power converter unit which takes the place of astandard clutch and transmission, such as used on an If used in anautomobile it can automobile, for example, which unit is eifective toconvert rotative mechanical power of the driving shaft into a lowerrotative speed and higher torque of the driven shaft and to do sosmoothly, with minimum friction loss, and with development of maximumhorsepower derived from/the prime mover. I am aware that variousmodifications will be readily suggested to those vskilled in the art,after having had the benefit of the teachings of the presentspecification such as the provision of more than two chambers, or `adifferent arrangement of slidable plates, etc., which modifications comewithin the purview and spirit of the present invention. Hence, I do notwish that the invention be limited except insofar as is set forth in thefollowing claims.

What I claim is:

l. A unitary hydraulic clutch and transmission unit comprising a drivingmember, a driven member, a hollow drum rigidly connected to the drivenmember, a second hollow drum eccentrically mounted with respect to andinside said lirst hollow drum in a liquid-tight manner, a body of liquidcontained in the space between said drums, a plurality of radiallyextending partition walls including radially inwardly biased slidableportions disposed between said drums to divide the space into twosemi-circular compartments, said eccentrically mounted hollow drumeiecting alternate pressure impulses in said compartments which aretransmitted to said partition walls and, in turn, to said outer drum anddriven member, said eccentrically mounted hollow drum having movableperipheral wall portions, means normally resiliently biasing saidmovable wall portions radially inwardly of said eccentrically mounteddrum to provide liquid escape openings between said compartments, andmeans under influence of centrifugal force of said driving member tooppose the inwardly biasing force on said movable wall portions and varythe liquid escape openings proportional to centrifugal force of saiddriving member.

2. A unitary hydraulic power converter comprising a container having aneccentric rotatably mounted therein, means for sealing the relativelymovable parts of said container and eccentric, the'space between saidcontainer and'said eccentric being lled with liquid, means forcontinuously dividing said space into two chambers irrespective of theposition to which the eccentric is rotated so as to cause alternatepressure surges in said chambers in succession, a drive shaft rigidlyconnected to said eccentric and a driven shaft rigidly connected to saidcontainer for transmitting torque as the result of unbalanced liquidpressure exerted on the areas of said partitioning members as aconsequence l0f rotation of said eccentric, said eccentric havingmovable peripheral wall portions, means normally resiliently biasingsaid peripheral wall p0rtions radially inwardly of said eccentric toprovide liquid escape openings between said two chambers, and meansunder inuence of centrifugal force of said driven shaft to oppose theinwardly biasing force on said peripheral wall portions and vary theescape openings proportional to centrifugal force of said drive shaft.

.3. A unitary hydraulic clutch and transmission unit comprising adriving member, a driven member, a hollow drum rigidly connected to thedriven member, a second hollow drum eccentrically mounted with respectto and inside said iirst hollow drum in a liquid-tight manner, a

7 -body of liquid contained inthe space between -saiddrums, and-aplurality of radially extending partition walls including radiallyinwardly biased slidable portions disposed between fsaid -drum-s todivide the space into two semi-circular coin- 'partmenta said-.eccentrically mounted .hollow drum :effecting alternate pressureimpulses in said compartments which are transmitted to said partitionwalls and, in turn, .to `said -outer drum and driven member, saideccentrically -rotatable inner drum including radially inwardlydepressible sliding bloc-k means havingan arcuiate surface conforming toAthe 'outer surface of .the .inner drum to allow-escape Vof liquidfromfone semi-circular compartment to thfe'other-between said slidingblock means and -slidable partition wall portion upon attainment -of,predetermined pressure.

4. A unitary hydraulic clutch and transmission Vunit comprising adriving member, a driven member, a hollow drum rigidly connected to thedriven member, a second hollow drum eccentrically mounted with respectto and inside said rst `hollow drum in a liquid-tight manner, a body ofliquid contained in the space between said drums, and a plurality ofradially extending partition walls including radially inwardly biasedslidable portions disposed between said drums to divide the space intotwo semi-circular compartments, said .eccentrically mounted hollow drumeecting alternate pressure impulses in said compartments which aretransmitted to said partition walls and, in turn, to said outer drum anddriven member, said inner, concentrically rotatable, drum having a pairof peripherally cut out portions, radially inwardly eX- tending .armsintegrally formed on said portions to provide piston-like members, and acam substantially the shape kof a truncated cone concentrically disposedand longitudinally slidable with respect to said drive shaft and Ahavinggrooves disposed longitudinally of the outer surface for engaging theends of said arms for longitudinally slidable movement so as to allowthe arms to move radially inwardly to depress said arcuate blocks inresponse to attainment of aA high predetermined pressure .in saidcompartments and thereby provide a liquid escape opening betweencompartments Vdisposed between said cut out portions and said slidablepartition portions.

V5. A unitary hydraulic power Vconverter comprising a container `havingAan eccentric rotatably mounted therein, means .forsealing therelatively movable parts of said container and ,eccentric, the spacebetween said container and said eccentric being filled lwith liquid,means for continuously dividing .said space -nto two .chambersirrespective of the position to which the eccentric is rotated so as tocause alternate pressure surges in said chambers in succession, .a.drive shaft rigidly connected to -said .eccentric anda driven shaftrigidly connected to said Acontainer for transmitting torque as theresult .of unbalanced liquid pressure exerted on the .areas -of saidpartitioning members as a-consequence .of rotation of said eccentric,ysaid eccentric `.having a plurality of fout-away portions along itsperiphery .integrally secured to Vradially inwardly extending armsforming piston like members which are depressible in response toattainment of Va predetermined pressure l.in =said 4chambers land meansforsimultaneously:movingsaid piston like members radially inwardly whensaid driven member is at rest.

6. Apparatus recited in vclaim 4 together with a vspring Vfor .normallybiasing said scam longitudinally in a directionso as'to vcauseradiallyiinward movement of said arms .and thereby provide a liquidescape opening when the driven shaft iis at rest.

7. Apparatus recited vin claim :5 wherein 'said arcuate Acut awayportions are provided .with grooves fior allowing'liquid toow'thereunder 'as the cut away portions are moved radially outwardlyunder the action of centrifugal force of the driving member.

GEORGE H. IRAMSEY.

REFERENCES CITED The following references are of record in the rile 'ofthis patent:

UNITED STATES 'QATEA- yIS Number Name Date -1,l49;970 Taft Aug. 10, 19152,175,970 Perkins Oct. 410, '1-939 2,238,786 Warman Apr. 15, "l1-94:12,313,049 Cook Mar. 9, vv1943 2,052,429 Tyler Aug. '25, '1946 2,451,118Pyle Oct. 112, 1948

